// SPDX-License-Identifier: GPL-2.0-only
/*
* ONIE tlv NVMEM cells provider
*
* Copyright (C) 2022 Open Compute Group ONIE
* Author: Miquel Raynal <[email protected]>
* Based on the nvmem driver written by: Vadym Kochan <[email protected]>
* Inspired by the first layout written by: Rafał Miłecki <[email protected]>
*/
#include <linux/crc32.h>
#include <linux/etherdevice.h>
#include <linux/nvmem-consumer.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#define ONIE_TLV_MAX_LEN 2048
#define ONIE_TLV_CRC_FIELD_SZ 6
#define ONIE_TLV_CRC_SZ 4
#define ONIE_TLV_HDR_ID "TlvInfo"
struct onie_tlv_hdr {
u8 id[8];
u8 version;
__be16 data_len;
} __packed;
struct onie_tlv {
u8 type;
u8 len;
} __packed;
static const char *onie_tlv_cell_name(u8 type)
{
switch (type) {
case 0x21:
return "product-name";
case 0x22:
return "part-number";
case 0x23:
return "serial-number";
case 0x24:
return "mac-address";
case 0x25:
return "manufacture-date";
case 0x26:
return "device-version";
case 0x27:
return "label-revision";
case 0x28:
return "platform-name";
case 0x29:
return "onie-version";
case 0x2A:
return "num-macs";
case 0x2B:
return "manufacturer";
case 0x2C:
return "country-code";
case 0x2D:
return "vendor";
case 0x2E:
return "diag-version";
case 0x2F:
return "service-tag";
case 0xFD:
return "vendor-extension";
case 0xFE:
return "crc32";
default:
break;
}
return NULL;
}
static int onie_tlv_mac_read_cb(void *priv, const char *id, int index,
unsigned int offset, void *buf,
size_t bytes)
{
eth_addr_add(buf, index);
return 0;
}
static nvmem_cell_post_process_t onie_tlv_read_cb(u8 type, u8 *buf)
{
switch (type) {
case 0x24:
return &onie_tlv_mac_read_cb;
default:
break;
}
return NULL;
}
static int onie_tlv_add_cells(struct device *dev, struct nvmem_device *nvmem,
size_t data_len, u8 *data)
{
struct nvmem_cell_info cell = {};
struct device_node *layout;
struct onie_tlv tlv;
unsigned int hdr_len = sizeof(struct onie_tlv_hdr);
unsigned int offset = 0;
int ret;
layout = of_nvmem_layout_get_container(nvmem);
if (!layout)
return -ENOENT;
while (offset < data_len) {
memcpy(&tlv, data + offset, sizeof(tlv));
if (offset + tlv.len >= data_len) {
dev_err(dev, "Out of bounds field (0x%x bytes at 0x%x)\n",
tlv.len, hdr_len + offset);
break;
}
cell.name = onie_tlv_cell_name(tlv.type);
if (!cell.name)
continue;
cell.offset = hdr_len + offset + sizeof(tlv.type) + sizeof(tlv.len);
cell.bytes = tlv.len;
cell.np = of_get_child_by_name(layout, cell.name);
cell.read_post_process = onie_tlv_read_cb(tlv.type, data + offset + sizeof(tlv));
ret = nvmem_add_one_cell(nvmem, &cell);
if (ret) {
of_node_put(layout);
return ret;
}
offset += sizeof(tlv) + tlv.len;
}
of_node_put(layout);
return 0;
}
static bool onie_tlv_hdr_is_valid(struct device *dev, struct onie_tlv_hdr *hdr)
{
if (memcmp(hdr->id, ONIE_TLV_HDR_ID, sizeof(hdr->id))) {
dev_err(dev, "Invalid header\n");
return false;
}
if (hdr->version != 0x1) {
dev_err(dev, "Invalid version number\n");
return false;
}
return true;
}
static bool onie_tlv_crc_is_valid(struct device *dev, size_t table_len, u8 *table)
{
struct onie_tlv crc_hdr;
u32 read_crc, calc_crc;
__be32 crc_be;
memcpy(&crc_hdr, table + table_len - ONIE_TLV_CRC_FIELD_SZ, sizeof(crc_hdr));
if (crc_hdr.type != 0xfe || crc_hdr.len != ONIE_TLV_CRC_SZ) {
dev_err(dev, "Invalid CRC field\n");
return false;
}
/* The table contains a JAMCRC, which is XOR'ed compared to the original
* CRC32 implementation as known in the Ethernet world.
*/
memcpy(&crc_be, table + table_len - ONIE_TLV_CRC_SZ, ONIE_TLV_CRC_SZ);
read_crc = be32_to_cpu(crc_be);
calc_crc = crc32(~0, table, table_len - ONIE_TLV_CRC_SZ) ^ 0xFFFFFFFF;
if (read_crc != calc_crc) {
dev_err(dev, "Invalid CRC read: 0x%08x, expected: 0x%08x\n",
read_crc, calc_crc);
return false;
}
return true;
}
static int onie_tlv_parse_table(struct nvmem_layout *layout)
{
struct nvmem_device *nvmem = layout->nvmem;
struct device *dev = &layout->dev;
struct onie_tlv_hdr hdr;
size_t table_len, data_len, hdr_len;
u8 *table, *data;
int ret;
ret = nvmem_device_read(nvmem, 0, sizeof(hdr), &hdr);
if (ret < 0)
return ret;
if (!onie_tlv_hdr_is_valid(dev, &hdr)) {
dev_err(dev, "Invalid ONIE TLV header\n");
return -EINVAL;
}
hdr_len = sizeof(hdr.id) + sizeof(hdr.version) + sizeof(hdr.data_len);
data_len = be16_to_cpu(hdr.data_len);
table_len = hdr_len + data_len;
if (table_len > ONIE_TLV_MAX_LEN) {
dev_err(dev, "Invalid ONIE TLV data length\n");
return -EINVAL;
}
table = devm_kmalloc(dev, table_len, GFP_KERNEL);
if (!table)
return -ENOMEM;
ret = nvmem_device_read(nvmem, 0, table_len, table);
if (ret != table_len)
return ret;
if (!onie_tlv_crc_is_valid(dev, table_len, table))
return -EINVAL;
data = table + hdr_len;
ret = onie_tlv_add_cells(dev, nvmem, data_len, data);
if (ret)
return ret;
return 0;
}
static int onie_tlv_probe(struct nvmem_layout *layout)
{
layout->add_cells = onie_tlv_parse_table;
return nvmem_layout_register(layout);
}
static void onie_tlv_remove(struct nvmem_layout *layout)
{
nvmem_layout_unregister(layout);
}
static const struct of_device_id onie_tlv_of_match_table[] = {
{ .compatible = "onie,tlv-layout", },
{},
};
MODULE_DEVICE_TABLE(of, onie_tlv_of_match_table);
static struct nvmem_layout_driver onie_tlv_layout = {
.driver = {
.name = "onie-tlv-layout",
.of_match_table = onie_tlv_of_match_table,
},
.probe = onie_tlv_probe,
.remove = onie_tlv_remove,
};
module_nvmem_layout_driver(onie_tlv_layout);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Miquel Raynal <[email protected]>");
MODULE_DESCRIPTION("NVMEM layout driver for Onie TLV table parsing");
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